Helleborus plant named ‘COSEH 4600’

ABSTRACT

A new and distinct cultivar of Helleborus plant named ‘COSEH 4600’, characterized by its relatively tall, upright and mounding plant habit; moderately vigorous growth habit; dark green-colored leaves; freely flowering habit; single dark greyed purple-colored flowers; and good garden performance.

Botanical designation: Helleborus x ericsmithii X Helleborus x hybridus.

Cultivar denomination: ‘COSEH 4600’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofHelleborus plant, botanically known as Helleborus x ericsmithii XHelleborus x hybridus and hereinafter referred to by the name ‘COSEH4600’.

The new Helleborus plant is a product of a planned breeding programconducted by the Inventor in Glandorf, Germany. The objective of thebreeding program was to create new uniform Helleborus plants with uniqueand attractive plant habit, leaf and flower coloration and resistance topests common to Helleborus plants.

The new Helleborus plant originated from a cross-pollination conductedby the Inventor in Glandorf, Germany in 2012 of a unnamed selection ofHelleborus x ericsmithii, not patented, as the female, or seed parentand an unnamed selection of Helleborus x hybridus, not patented, as themale, or pollen parent. The new Helleborus plant was discovered andselected by the Inventor as a single flowering plant from within theprogeny of the stated cross-pollination grown in a controlled greenhouseenvironment in Glandorf, Germany in 2014.

Asexual reproduction of the new Helleborus plant by divisions in acontrolled environment in Glandorf, Germany since 2015 has shown thatthe unique features of this new Helleborus plant are stable andreproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possiblecombinations of environmental conditions and cultural practices. Thephenotype may vary somewhat with variations in environmental conditionssuch as temperature and light intensity without, however, any variancein genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘COSEH 4600’. These characteristics incombination distinguish ‘COSEH 4600’ as a new and distinct Helleborusplant:

-   -   1. Relatively tall, upright and mounded plant habit.    -   2. Moderately vigorous growth habit.    -   3. Dark green-colored leaves.    -   4. Moderately freely flowering habit.    -   5. Single dark greyed purple-colored flowers.    -   6. Good garden performance.

Plants of the new Helleborus and the parent selections differ primarilyin flower color as plants of the female parent selection have flowersthat are pink in color and plants of the male parent selection haveflowers that are red in color. In addition, plants of the new Helleborusare taller than plants of the female and male parent selections.

Plants of the new Helleborus can be compared to plants of Helleborus xhybridus ‘ABCRD02’, disclosed in U.S. Plant Pat. No. 24,720. Inside-by-side comparisons, plants of the new Helleborus differ primarilyfrom plants of ‘ABCRD02’ in flower color as plants of ‘ABCRD02’ haveflowers that are lighter purple in color.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Helleborus plant showing the colors as true as it isreasonably possible to obtain in colored reproductions of this type.Colors in the photographs may differ slightly from the color valuescited in the detailed botanical description which accurately describethe colors of the new Helleborus plant.

The photograph on the first sheet is a side perspective view of atypical flowering plant of ‘COSEH 4600’ grown in a container.

The photograph on the second sheet is a close-up view of a typicalflower of ‘COSEH 4600’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurementsand values describe plants grown during the winter in 17-cm containersin a glass-covered greenhouse in Glandorf, Germany and under culturalpractices typical of commercial Helleborus production. During theproduction of the plants, day temperatures ranged from 12° C. to 24° C.and night temperatures ranged from 3° C. to 18° C. Plants were 14 monthsold when the photographs and the description were taken. In thefollowing description, color references are made to The RoyalHorticultural Society Colour Chart, 2015 Edition, except where generalterms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus x ericsmithii X Helleborus x    hybridus ‘COSEH 4600’.-   Parentage:    -   -   Female, or seed, parent.—Unnamed selection of Helleborus x            ericsmithii, not patented.        -   Male, or pollen, parent.—Unnamed selection of Helleborus x            hybridus, not patented.-   Propagation:    -   -   Type.—In vitro rhizome culture.        -   Time to initiate roots, winter.—About two months at            temperatures about 12° C.        -   Time to produce a rooted young plant, winter.—About six            months at temperatures ranging from 4° C. to 15° C.        -   Root description.—Thick to thin, fleshy; typically white to            brown in color, actual color of the roots is dependent on            substrate composition, water quality, fertilizer type and            formulation, substrate temperature and physiological age of            roots.        -   Rooting habit.—Sparse.-   Plant description:    -   -   Plant and growth habit.—Herbaceous perennial; relatively            tall, upright and mounding plant habit with flowers held            above the foliar plane; plant shape, roughly flattened            globular; moderately vigorous growth habit; moderate growth            rate.        -   Plant height, soil level to top of foliar plane.—About 32            cm.        -   Plant height, soil level to top of flowers.—About 42.8 cm.        -   Plant diameter (area of spread).—About 43.1 cm.-   Leaf description:    -   -   Arrangement.—Leaves arranged in a basal rosette; leaves            palmately compound with typically five leaflets per leaf.        -   Leaf length.—About 19.5 cm.        -   Leaf width.—About 18.4 cm.        -   Leaflet length.—About 12.7 cm.        -   Leaflet width.—About 7.2 cm.        -   Leaf shape.—Palmate; reniform in outline.        -   Leaflet shape.—Obovate to elliptic.        -   Leaflet apex.—Short apiculate to acute.        -   Leaflet base.—Attenuate.        -   Leaflet margin.—Coarsely serrate; moderately undulate.        -   Leaflet texture and luster, upper surface.—Slightly rugose,            glabrous; moderately leathery; moderately glossy.        -   Leaflet texture and luster, lower surface.—Slightly rugose,            glabrous; moderately leathery; slightly glossy.        -   Leaflet venation pattern.—Pinnate.        -   Leaflet color.—Developing leaflets, upper surface: Close to            between NN137A and 147A. Developing leaflets, lower surface:            Close to between N186C and N200A. Fully developed leaflets,            upper surface: Close to darker than between 147A and N189A;            venation, close to 147B. Fully developed leaflets, lower            surface: Close to 143A to 143B; proximally tinged with close            to between N186C and 200A; venation, close to 187B.        -   Petioles.—Length: About 14.4 cm. Diameter: About 5.5 mm to            6.5 mm. Strength: Strong. Texture and luster, upper and            lower surfaces: Smooth, glabrous; moderately glossy. Color,            upper and lower surfaces: Close to 144B; moderately to            densely covered with small spots, close to 187A and 187B.-   Flower description:    -   -   Flower shape and habit.—Single rotate flowers; arranged            solitary or in small clusters with about five flowers each;            moderately freely flowering habit with about 25 flowers            developing per plant; flowers facing outwardly to nodding.        -   Fragrance.—None detected.        -   Natural flowering season.—Plants begin flowering about ten            months after planting; plants flower during the winter in            Germany.        -   Flower longevity on the plant.—About ten days; sepals            persistent, other flower parts not persistent.        -   Flower buds.—Length: About 2.4 cm. Diameter: About 1.7 cm.            Shape: Broadly ovoid. Texture and luster: Smooth, glabrous;            matte. Color: Close to between N186C and 187A.        -   Inflorescence height.—About 23.6 cm.        -   Inflorescence diameter.—About 18.7 cm.        -   Flower diameter.—About 7.2 cm.        -   Flower depth (height).—About 3.8 cm.        -   Petals.—Transformed into nectaries.        -   Sepals.—Quantity and arrangement: About five, arranged in a            single whorl. Length: About 5.5 cm. Width: About 5.3 cm.            Shape: Broadly ovate to nearly orbicular, moderately to            slightly concave. Apex: Obtuse. Base: Cuneate. Margin:            Entire; very slightly undulate. Texture and luster, upper            surface: Smooth, glabrous; matte. Texture and luster, lower            surface: Smooth, glabrous; slightly glossy. Color: When            opening, upper and lower surfaces: Close to N186C and            slightly darker than N186C. Fully opened, upper surface:            Close to between N186C and 187A. Fully opened, lower            surface: Close to N186C tinged and marbled with close to            187A and 187B.        -   Flower bracts.—Quantity per flower: Typically two. Length:            About 4.4 cm to 11 cm. Width: About 3 cm and 6.5 cm. Shape:            Ovate. Apex: Acute. Base: Broadly cuneate. Margin: Serrate;            slightly undulate. Color, upper surface: Darker than between            NN137A and 147A. Color, lower surface: Darker than between            N186C and 200A.        -   Peduncles.—Length: About 39.1 cm. Diameter: About 8 mm to            12 mm. Aspect: About 10° from vertical. Strength: Strong.            Texture and luster: Smooth, glabrous; moderately glossy.            Color: Close to 144C; flushed and densely covered with small            spots, close to 187A to 187B.        -   Pedicels.—Length: About 6 cm. Diameter: About 3.5 mm to            4 mm. Aspect: About 35° from peduncle axis. Strength:            Moderately strong. Texture and luster: Smooth, glabrous;            glossy. Color: Close to between N186C and 200A.        -   Reproductive organs.—Stamens: Quantity per flower: About 90.            Filament length: About 1.8 cm. Filament color: Close to            N155B tinged with close to 186D. Anther shape: Reniform;            basifixed. Anther size: About 1.75 mm by 3 mm. Anther color:            Close to 1C. Pollen amount: Scarce. Pollen color: Close to            4D. Pistils: Quantity per flower: About four. Pistil length:            About 1.5 cm. Stigma diameter: About 0.3 mm. Stigma shape:            Club-shaped. Stigma color: Close to 157A. Style length:            About 1.45 cm. Style color: Close to N186C. Ovary color:            Close to N186C. Nectaries (transformed petals): Quantity per            flower: About 12 to 14. Length: About 1.5 cm. Diameter:            About 4 mm. Shape: Tubular, flattened. Texture and luster,            inner and outer surfaces: Smooth, glabrous; matte. Color,            immature, inner and outer surfaces: Close to N144A to N144B.            Color, mature, inner and outer surfaces: Close to N144A;            distally, close to 151B; distal color becoming closer to            153D with development.        -   Seeds and fruits.—Seed and fruit development have not been            observed on plants of the new Helleborus to date.-   Garden performance: Plants of the new Helleborus have been observed    to have good garden performance and to tolerate rain, wind and to be    suitable for USDA Hardiness Zones 5 through 9.-   Pathogen & pest resistance: Plants of the new Helleborus have not    been observed to be resistant to pathogens and pests common to    Helleborus plants to date.

It is claimed:
 1. A new and distinct Helleborus plant named ‘COSEH 4600’as illustrated and described.